Poly-N-vinyl carbazoles and derivatives thereof are substances widely used as organic photoconductors in the preparation of electrostatic photoconductive elements from which multiple copies can be produced in the duplicating field. By themselves, the poly-N-vinyl carbazoles and derivatives are not sufficiently photoconductive unless modified by the presence of varying amounts of acceptor type compounds, such as fluorenone derivatives, phthalic anhydride derivatives, halogenanil derivatives or ketone derivatives. In practice, the electron affinitive compound (acceptor compound) is blended with the polymer after polymerization of the carbazole monomers.
N-vinyl carbazole and its derivatives polymerize very slowly in the absence of a polymerization catalyst. For purposes of accelerating polymerization use has been made of a catalyst such as ditertiary butyl peroxide, azobisbutyronitrile, betanaphthol, monoethyl aluminum dichloride, and the like. The presence of such catalysts in the polymer often presents problems in the subsequent formation of the charge transfer complex or interferes in other ways with the selected acceptor. As a result, it has been the common practice to remove the catalyst from the polymer before formulating the polymer with the desired electron affinitive compoiund, if the polymer is to be used as a photoconductor. Such separation steps are costly and time consuming and thus introduces a barrier to the commercial acceptance of photoconductive elements fabricated of such organic photoconductors.